1
Q
what is the ultimate goal of viruses
A
to replicate itself, causes disease along the way by destroying cells
2
Q
similarities between viruses
A
there’s no common structure(all evolved separately) but similarities are:
-ver small- <100 nanometers don’t have cells
-some kind of genetic materal-different forms-DNA or RNA
-Capsids
-some have enzymes, most dont
3
Q
what are capsids
A
the container/shell that holds DNA
-different shapes
-made of proteins-usually 1 kind
-proteins can be used to attach or attack- immune system can use at antigen
4
Q
where does diversity of viruses come from
A
genes-none are shared
-type of genetic material:DNA or RNA
-strand #: 1 or 2 for either
-shape: circular or linear
-enveloped: some of cell membrane taken by virus when virus bursts-mainly animals
-non-enveloped: don’t take membrane- mainly bacteria and plants
8 possibilities
5
Q
what is a bacteriophage
A
virus that attacks bacteria
6
Q
features of coronavirus
A
-enveloped
-single strand RNA
-attacks mainly lung cells
7
Q
features of HIV
A
-enveloped
-single strand RNA to start, becomes double stranded
-infects helper-t cells
-reverse transcriptase: enzyme that turns RNA into DNA- makes almost impossible to get rid of
8
Q
2 options for how virus infects and duplicates
A
- do quickly
- take breaks between injection and usage
most viruses can do both
9
Q
basic idea of virus infecting
A
inject nucleic acid, get it to make viral proteins, proteins become new virus, new virus burst from cell and kill it
10
Q
what is the lytic cycle
A
kills host cell right away
11
Q
steps of bacteriophage lytic cycle
A
- bind to host cell- e.coli
-tail of bacteriophage attaches to e.coli membrane proteins that is used for absorption - inserts DNA into pore opened from step 1
- DNA copied
- DNA transcribed
5.mRNA translated into proteins that make virus
6.lysis: breaks outer wall - virulence: bursting and killing of cell`
12
Q
what is the lysogenic cycle
A
takes break after injecting DNA while cell copies itself
13
Q
origin of viruses
A
unclear- they don’t leave evidence
probably from multiple sources at multiple different times
more simple=more likely to have evolved at many different times
13
Q
steps of lysogenic cycle
A
- virus binds to host cell-e.coli
- inserts DNA through channel
- enzymes from virus integrate into DNA of host
- e.coli replicates-makes more dna- DNA all contains virus DNA
-lytic cycles occurs in usually single celled organism
-sometimes virus stays in host forever
14
Q
hypothesis that viruses came before cells
A
viruses are simpler, but cant survive without host cells now at least
viruses could’ve evolved from cells
15
Q
how are viruses examples of convergent evolution
A
-all are obligate parasites:forced to be parasites
-same generic code
-other genetic codes would’ve died out because they wouldn’t be able to survive off cells with our genetic code
16
Q
3 reasons for the rapid rate of evolution in viruses
A
- quickly reproducing-could be mutation every time
- higher mutation rates-DNA isn’t proofread
- high natural selection pressure because of the way immune system works to fight them
17
Q
examples of virus with rapid rates of evolution
A
1.influenza: 8 chromosomes, 8 strands of RNA-high chance of mutating
2. HIV: uses enzyme to turn RNA to DNA, adds steps which adds more opportunity for mutations
-1 person can have multiple forms of virus
18
Q
when is a virus mutation helpful for the virus
A
if the antigen changes and immune system cant recognize
-viruses with mutated antigens left behind, others die
19
Q
function of alveoli
A
gas exchange from alveoli to blood by capillaries surrounding alveoli and back to the alveoli
20
Q
2 types of cells in lung tissue
A
type 1 pneumocytes: cells that gases are going across- permeable,thing, barely have organelles, small
type 2 pneumocytes: make fluids, increase gas exchange rate, make up surfactants to break up non polar things to keep alveoli from sticking to each other- wider, larger, full of ribosomes and smooth/rough ER, make lots of phospholipids to expand cells
21
Q
what is blood mostly made up of
A
water-very polar
22
Q
is oxygen polar or non polar
A
very non polar- doesnt bind with water
23
Q
what is hemoglobin
A
non polar protein that binds to oxygen
made of 4 polypeptides
made of 4 heme groups within- the non polar part
-conjugated
24
what happens when 1 hemoglobin binds to 1 oxygen
there is a change in the rest of the molecule
increases affinity for binding to oxygen
-called cooperative binding
25
how does amount of oxygen in atmosphere affect binding
very little oxygen, 0 binding
just a few more, all 4 bind
no middle ground
26
carbon dioxide
waste product of cells, delivered to lungs to be breathed out
non polar
binds to hemoglobin in different spot-allosteric site
27
what happens when co2 binds to hemoglobin
shape of hemoglobin changes which decreases its affinity for co2
oxygen detaches
28
process of CO2 usage
CO2 made by cell respiration, binds to hemoglobin, hemoglobin releases O2, O2 used for more cell respiration
CO2 goes back to lungs to be exhaled
29
what is the Bohr shift
the shift in oxygen affinity when more CO2 is present
plateau is still reached, but takes more oxygen
30
direction of shift
right: lower affinity
left: higher affinity
31
example of something with high oxygen affinity
developing fetus hemoglobin
32
capillaries
very small and thin
must be near every cell
takes blood to specific places
33
structure of blood
Blood cells
-stay in blood
-carry hemoglobin
Plasma
-liquid, mainly water
-leaves capillaries by pores
-filtrated by capillaries
-dissolves everything that needs to move
-transports
34
what is tissue fluid
stuff filtered out of plasma by capillaries
35
what are arterioles
branches that bring fluid from capillaries to arteries
-push out proteins, hormones etc to deliver
-high pressure
36
what are venules
branches that bring fluid back into veins
-waste products
-low pressure
37
What is required to actually move molecules across cells
Concentration gradients
high oxygen outside in the pushed out tissue fluid-is immediately used up inside
Waste products high inside cell-goes back to capillaries and back to lungs or kidneys
38
2 reasons that not all tissue fluid reenters circulatory system
1. not as many capillaries in area
2. capillaries too full
causes buildup that needs reabsorbed
39
where does tissue fluid go to be reabsorbed
lymphatic system- now called lymph
40
functions of lymphatic system
transport, making WBCs, has stem cells
41
lymphatic vessel features
-small vessels, big enough to absorb more fluid
-valves to make sure lymph goes into right direction
-low pressure
42
what are lymph ducts
receiving areas, usually connected to vein to make sure it gets back into circulatory system
43
2 main ways of heart making circulation
1. mammal hearts-double circulation
2. fish hearts- single circulation
44
what is double circulation
-1 side pumps to lungs to be oxygenated and back to heart- pulmonary circulation
-1 side pumps to rest of body- systemic circulation
45
single circulation in fish
-fish blood pumped to gills-oxygen absorbed right to gills
-water pressure forces oxygen into blood which goes to body-why fish move
-oxygen used and blood back to heart
46
steps of pulmonary circulation
1. right ventricle pumps blood
2. pulmonary artery takes to lungs to be oxygenated
3. oxygenated blood goes to left atrium-comes in by pulmonary vein
4. blood pushed to left ventricle
47
steps of systemic circulation
5. blood starts in left ventricle and is pumped out through aorta-biggest artery- to rest of body
-oxygen used up
6. deoxygenated blood goes to right atrium by vena cava
7. blood then goes to right ventricle for pulmonary circulation
48
valves of cardiac cycle
semilunar: between ventricle and artery
atrioventricular: between atrium and ventricle
49
what is the septum of the heart
separates heart to keep oxygenated and deoxygenated blood from mixing due to double pump
50
what do coronary vessels do
heart muscles cant use the oxygen from the cardiac cycle so it pumps blood to itself through coronary vessels
51
what is the sinotrial node
group of cells that cause heart to beat-control the change in charge(depolarization)
52
what does myogenic mean
muscle in charge of itself
-cardiac muscle
53
what is heart rate controlled by
nervous system
54
what happens when heart beats
-atria contract-blood pumped to ventricles-pressure increases- valve opened
-ventricles contract-blood pumped out through arteries- pressure increases then increases even more, valve opened, then decreases when blood leaves, valve shurt
55
systolic vs diastolic pressure
systolic: brief increase when heart pumps blood
diastolic: constant pressure
56
what is skeletal muscle
attached to bones, move bones around
57
cardiac muscle
heart muscles, myogenic
58
smooth muscle
around blood vessels and digestive system-enteric nervous system
59
what are muscle fibers
bundles of many muscle cells fusing together-lots of nuclei
60
unique muscle cell traits
-many nuclei
-large cell membrane: sarcolemma
-sarcoplasmic reticulum: in charge of calcium ions/nerve impulses
-highest number of mitochondria
61
what are myofibrils
protein structures inside muscle cell where muscle contraction occurs
62
what are z lines
dark lines that segment each myofibril
63
what is a sarcomere
where contraction occurs at molecular level
64
Actin and myosin
2 proteins that interact to make contractions happen
Actin:light filament, only proteins at z lines, 6 for each myosin
Myosin: pulls actin to middle
muscle fibers shorten
65
how does muscle contraction start
signal from motor neuron- acetylcholine
acetylcholine crosses neuromuscular junction from motor neuron to muscle cells
cells act in coordinated fashion
66
what do myosin heads do
part that actually pulls actin
lots of potential energy stored
67
what are cross bridges
myosin heads binding to actin
-automatic binding-doesnt use energy
68
what does ATP do for muscle contractions
used for the pull
breaks crossbridge so it can reform at next actin binding site
69
what releases myosin
swiveling of myosin head
70
when does muscle contraction process stop
if muscle is fully contracted or if signal tells muscle to stop
71
what is titin
protein attached to myosin that attaches to z line and pushes Actin back outwards
-prevents over contracting
72
how do different organisms move
bacteria: flagelli and pilli
amoeba: extending and retracting
plants: growth if you count it, movement of flowers
animals: flying, swimming, walking
73
what does motile mean
organisms that can move
-small or large distances
74
what does sessile mean
organisms that have little to no movement
-plants, fungi, coral, sponges
75
reasons for locomotion
get more energy:finding food
escaping from danger
searching for mate:reproduction
migration: weather, food, or breeding
-giant use of energy but still beneficial
76
why are dolphins and whales unique
ancestors lived on lands but got adaptations to live in water- like the only marine mammals
77
adaptation of marine animals to be able to live in water
1. streamlining shape: shape to minimize water resistance- narrow point at front, wider in middle, narrow in back
2. minimal hair
3. back limbs gone
-floating hipbones- vestigial
4. no ear flaps
78
adaptations for marine animals to swim better
1. front flippers
2. flukes: split of tail for propulsion
3. dorsal fin: stability so they dont spin in water
4. blowhole for ventilation: movement of air in and out
-blowhole connected to lung
-helpful because air is above them and water wont go in mouth and into lungs while swimming
79
adaptive immune response
phagocytes find pathogen and engulfs and destroys it
-antigen is saved
phagocyte displays antigen on its surface
helper t cells recognizes antigen and is activated
B cell sees same pathogen
b cell and t cell bind together activating the b cell
b cells divides by mitosise into many cells
cells make and release antibodies
antibodies destroy pathogens or help phagocytes destroy pathogen
antibodies and b cells all dissolve except some b cells
80
pre synapse to post synapse transmission steps
1.signal reaches end of pre synaptic membrane
2. when it reaches end, the last depolarization causes calcium(+2) channels to open
3. drastic increase in charge tells vesicles carrying transmitters to fuse with outer membrane of pre synaps
4. neurotransmitters are released
5. neurotransmitters diffuse from pre synaps to post synaps across cleft
6. neurotransmitters bind to membrane protein on the post synaptic membrane
7. sodium channels open
8. sodium ions diffuse into post synaptic neuron
9. action potential is generated
10. neurotransmitters are broken down and can diffuse back
81
names of atrioventricular valves
right: tricuspid
left:bicuspid or mitral
82
what does the skeleton do
anchors muscles to body, together they act as levers to make body move
83
Endo vs exoskeleton
endoskeleton: muscles wrap around skeleton
exoskeleton: skeleton on outside of muscles
84
body levers
fulcrum/pivot point: bone that doesn't move
effort force: makes lever move-created by muscles
resultant force: movement of bone from effort force
85
how are levers connected
muscles and tendons
86
what are antagonistic muscles
muscles that work in opposite fashion
ex: lungs
87
what is a joint
where 2 bones meet
88
what is articulation
how 2 bones move in relation to each other
89
what is cartilage
lines bones and decrease friction
90
what does synovial fluid do
prevents friction
91
what is a ligament
connects bone to bone, keeps synovial fluid in
92
tendons
connect muscle to bone
93
what is a hinge joint
has 2 way movement: knees, elbows
-flexion and extension
94
ball and socket joint
many different ways: shoulders, hips
-protraction and retraction
-abduction and adduction
-rotation
95
what is a goniometer
2 rulers attached that measure ROM
iv ex: age, disease, athleticism
96
what is resting potential
signal isn't being sent
created by sodium-potassium pump
97
what is the sodium potassium pump
sodium is pumped out, potassium pumped in- creates concentration gradients
98
process of action potential
1.signal sent, slightly increases to threshold potential
2. sodium channel opens, sodium flows in and charge goes way up(depolarization)
3. potassium channel opens, potassium flows out and charge goes away back down(repolarization)
4. pump reestablishes resting potential
4. action potential moves down axon
99
how long does depolarization and repolarization take
1-2 milliseconds
100
what does voltage gated mean
the opening and closing of channels due to change in charge
101
what is the threshold potential
minimum for sodium channels to open~-50mb
-slightly above resting potential(-70mb)
102
what are local currents
when action potential moves to next part of axon due to leftover sodium that flows in from concentration gradient
-sodium flows to next part, increases charge hopefully to threshold potential to start action potential
103
what is an oscilloscope
use electrodes to measure rapid changes in charge
-reproduces graph on screen
104
what is saltatory conduction
using myelin to increase speed of action potential movement
-accumulation of channels and pumps in gaps, increases speed of local currents
105
what is myelin
lipid added to outside of axon
106
what are Schwann cells
they deposit myelin in groups-leave gaps
107
what are Nodes of Ranvier
gaps between groups of myelin/Schwann cells
108
what are exogenous chemicals
Any chemical that enters body
-often affects synaptic transmission
-can prevent pre synapse from sending signal but usually post synapse from receiving
109
2 examples of exogenous chemicals
1. neonicotinoids: block acetylcholine receptors, muscles don't work
-only affect insects- in pesticides
-controversy because they affect beneficial insects
2. cocaine: prevents reuptake of dopamine
-dopamine builds up
-damages neurons in long run
110
what are inhibitory neurotransmitters
inhibit signal from going places- regulate that they go to their specific place
-do hyperpolarization
111
what is hyperpolarization
decrease charge on neuron
112
what is GABA
most important and common inhibitory neurotransmitter that regulates brain function
-deficiency can cause mental disorders
113
purpose of neurotransmitters
get next neuron to threshold potential to start action potential
114
how does the sodium potassium pump impact neurostransmitters
sodium is constantly pumped out to reestablish resting potential, sometimes stops signal from being sent
115
what does body do to make sure signal is sent
increase to multiple pre synaptic neuron neurotransmitters for each post synaptic neuron
-most common in brain-specifically parts for complicated decision making
-balance between inhibitory and excitatory
116
reflex arc steps
signal from receptor, to sensory neuron, to integration center, to motor neuron, to effector
117
what are exposed nerve endings
detect pain
-highest # in eye
-have lots of Na/K channels to increase speed of signal to make sure it reaches or passes the brain- males motor neuron get body away from cause of pain
118
How do faster responses happen
goes directly to motor neurons within spinal cord- involuntary
119
how do slower responses happen
signal goes to brain
ex: heat,acid, puncturing, chemicals, emotions
120
definitions of consciousness
"I think, therefore I am" = conscious
state of complex awareness: aware of multiple things at once-able to think and evaluate
-interactions of many neurons at same time
121
what is emergent property
occurs from multiple things working together
-ex: life, thinking
122
process of fertilization
-sperm arrives at egg, found by egg signals (hormones)
-dissolves outser shell of egg by enzymes
-nucleus enters egg
-outer shell hardens
-zygote goes through mitosis to grow
123
adaptations of egg cell
-zona pellucida: outer shell- glycoproteins
-cortical granules: full of enzymes for hardening after 1st sperm enters
-yolk:cytoplasm in growing fetus
-mitochondria and MTOC: energy for a lot of mitosis
124
sperm adaptations
-tail/flagella: helps swim
-many mitochondria
-narrow nucleus
-acrosome: contains enzymes for wall breakdown- in head
125
puberty definition
transition between childhood and ability to reproduce
-controlled by hormones-mainly from pituitary gland
126
what starts puberty
Gonadotropin-releasing hormone GnRH-sent by hypothalamus to target pituitary gland
127
beginning of puberty for males
-begin production of testosterone in testis mainly
-then the production of sperm(primary sexual characteristics)
128
male secondary characteristics
-enlargening of penis to penetrate and to deliver sperm
-pubic hair
-deepening of voice
129
start of puberty in females
-LH and FSH target ovaries to start making estrogen and progesterone
-release of egg, start of menstruation-primary sexual characteristics
130
female secondary characteristics
-enlargement of breasts to give milk
-pubic hair
-enlargement of uterus
131
what is spermatogenesis
formation of sperm from seminiferous tubules within testis, starts by testosterone
132
spermatogenesis steps
1. germ cells make copies by mitosis- makes spermatogonia cells(diploid)
2. Meiosis 1 -primary spermatocytes
3. Meiosis 2- secondary spermatocytes
3. Spermatids made- get nutrients from Sertoli cells
4. Spermatozoa:full functional sperm (diagram)
133
what is oogenesis
formation of eggs in ovaries- starts while female is still in womb
134
steps of oogenesis
1. germ cells go through mitosis: make oocyte mother cells- all made during 1st 4 months of fetus development
2. primary oocytes go through meiosis I- make up primary follicles- unequal
3. remain primary follicles until menstrual cycle begins
4. 1 egg released per month during meiosis II, meiosis II finishes at fertilization
3 eggs made along way
135
what is unequal cytokinesis
makes 1 large egg cell and 1 small polar body that dissolves and doesn't do meiosis II
136
simple steps of fertilization
1. acrosome
2. penetration of sperm into egg
3. cortical reaction-prevents polyspermy
137
process of pregnancy
1. -zygote goes through lots of mitosis to form embryo- eventually become identical stem cells
2. differentiation causes lots of unequal cytokinesis
3. blastocyst made: ball of cells
4. gets nutrients from zona pellucida-zona pellucida shed
5. implants into endometrium to get nutrients, oxygen, antibodies- gives up CO2 for mother to exhale
6. becomes fetus once it has bone tissue
7. HCG tells corpus luteumm to keep lining of uterus so it keeps making estrogen and progesterone
138
process of pregnancy tests
Uses antibodies:good at attaching to other molecules and detecting certain molecules
antibodies attach to dye that can only attach if HCG hormone is present
139
how false negative tests are avoided
2 lines- make sure dye is there and antibodies attach
140
types of mammals pregnancy
placental
marsupial: in pouch
monotreme: eggs
141
monotremes
echnida and platypus
142
marsupials
possums, koalas, kangaroos
143
purpose/parts of placenta
maintain as much contacts between fetus and mother tissue- high surface area
amniotic sac and fluid: increase SA and prevent mixing
villi: ridges to increase SA
144
how do different molecules across placental barrier
O2: mother to fetus by diffusion
CO2: from placenta to mother by diffusion
sugars: from mother to fetus by facilitated diffusion-channels
antibodies: mother to fetus by endocytosis
h2o: both ways by osmosis
145
when does corpus luteum stop making progesterone and estrogen
4-5 months, when placenta begins making its own
146
what causes childbirth
estrogen and progesterone start decreasing which stops the inhibition of oxytocin
147
childbirth process
-oxytocin stimulates myometrium to cause to contract
-brain produces more which causes more contractions- positive feedback
-cervix dilates
-contractions Burt's amniotic sac and releases fluid
-contractions continue until baby is pushed out
- connection between mother and fetus continues until umbilical cord is cut
148
what is menopause
drastic decrease in production of progesterone and estrogen
-side effects: hot flashes, night sweats, mood swings
149
point of hormone replacement therapy
relieve symptoms by injecting with hormones similar to progesterone and estrogen that are only targeted at side effects
150
why did initial HRT research show lower rate of heart disease
they were already healthier because they were wealthy and could afford healthy lifestyles
151
2 main kidney functions
1. get waste into urine by osmoregulation
2. excretion
152
what is osmoregulation
keeping concentrations of glucose, salt, ions, nutrients steady in blood
-homeostasis
-kidneys not in charge of o2, sugars, or co2
153
blood coming in kidneys vs out
in: all diff concentrations
out: hopefully uniform
154
what is waste from kidneys mostly
nitrogen- urea
stored in bladder until released
155
what is a nephron
the main functional unit of the kidney- many within kidney
-tubes and ducts surrounded by capillaries that stretcg between medulla and cortex
156
what is a glomerulus
1st part of nephron with many capillaries
157
what is the afferent arteriole
go from artery to glomerulus
158
goal of glomerulus
get as much out by ultra filtration: push into tube of nephron
-large proteins and blood cells stay
159
what is the bowman's capsule
1st tube of nephron
160
barriers between bowman's capsule and glomerulus
fenestrations : small pores
basement membrane: charged layer
podocytes: cells with slits to let small things through
161
what is the efferent arteriole
leaves glomerulus
162
where does filtrate go after the glomerular filtrate
to the proximal convoluted tubule (PCT)
163
what does the PCT do
selective reapsorption: reabsorb important molecules by active transport back to nephron to capillaries
164
purpose of microvilli in PCT
line the inside to increase surface area for more absorption
165
Molecules reabsorbed by PCT
sodium(+): active transport
chloride(-): passively to balance charge
glucose:brought with sodium by cotransport
water: osmosis to dilute
166
where does filtrate go after PCT
loop of Henle- in medulla- high salt ions
167
what does the descending limb do
permeable to water- waste loses water to surrounding capillaries
168
what does the ascending limb do
not permeable- pushes out salts to keep medulla salty
169
what is the vasa recta
part of capillary around Loop of Henle
170
what does countercurrent multiplier mean
building of the concentration gradients in Loop of Henle
171
length of loop of Henle
longer= more water reclaimed by capillaries
-adaptation based off water availability
172
where does filtrate go after Loop of Henle
Distal convoluted tubule-runs through medulla
173
What is the collecting duct
-collect all filtrate from DCT
-all nephrons connect to
174
where does filtrate go after collecting duct
to ureter and then to bladder- last place water is collected
175
what are osmoreceptors
detect concentrations in blood in collecting duct
176
what happens if osmoreceptors detect high concentrations
signal is sent to hypothalamus which makes pituitary gland release antidiuretic hormone(ADH)
collecting duct becomes more water permeable
water exits onto medulla by concentration gradient and is absorbed by capillaries-meaning not in urine, why urine is dark
177
what happens when osmoreceptors detect low concentrations
pituitary gland doesnt send out ADH
collecting duct isn't permeable-water cant leave
water goes to bladder
178
what does blood supply to the urinary system depend on
area and situation body is in
179
3 different states for blood supply
1.vigorous exercise
2. resting while awake
3. deep sleep
180
4 places that need different amounts of blood supply in the 3 different states
1. skeletal muscle: high while exercising, low while asleep
2. digestive system: high during exercise, depends for other two
3. kidneys: high while resting, low for sleep and exercise
4. brain: high during exercise and sleep, low while resting
181
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